Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4a266461f4b31f3…

MALICIOUS

PDF

77.6 KB Created: 2021-03-20 16:48:55 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 914055b70c903b4e00e155334991ead4 SHA-1: 1a32b75ae362fee1f0d89fc60c44a839a8ddd460 SHA-256: c4a266461f4b31f377e8b0b62629729e51096dadabf06e4f5a0e850b8b146c8f
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm with numerous external URLs, one of which is vilenefex.ru, suggesting a phishing or malware distribution attempt. The document body, though partially corrupted, indicates a lure related to learning French, likely to trick users into visiting the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://vilenefex.ru/award?keyword=livre+complet+pour+apprendre+le+fran%25C3%25A7ais+pdf PDF link annotation
    • https://diwijavel.weebly.com/uploads/1/3/4/6/134691177/nevexiv-rubofepusexinu-kuwonu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445104/normal_5fe70c98f3eae.pdfIn PDF document text
    • https://sitegevom.weebly.com/uploads/1/3/4/6/134664280/rakobemijudi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449395/normal_602e2f873b6f2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412378/normal_6009d5b63e1c2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366335/normal_5fc918d22df39.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486535/normal_5ffcb7c77a481.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445881/normal_601da650cd078.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4505102/normal_5fda76ffcd9ad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426814/normal_600a4d08b2e6c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cfecb619-c0f5-418d-ae9d-b1147643389f.filesusr.com/ugd/4cd51e_fb7402fe290f4d35b1f4294627318e16.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wunupalezozerud/53496722315.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35d57d04-b304-4312-9b01-fff386f209bd/muxadidumoseporazusog.pdfIn PDF document text
    • https://s3.amazonaws.com/gotitibekovi/how_much_does_it_cost_to_fix_a_convection_oven.pdfIn PDF document text
    • https://6440a9f6-5e82-4153-977b-4ffe9374ec4a.filesusr.com/ugd/7182f3_35d5be44a6c241d18945a632545183a8.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f0f5381-980b-41a4-9d1d-54dbffb36cf5/voxetebirepifibogibe.pdfIn PDF document text
    • https://e50eee24-2d95-422d-8083-6f618d95927b.filesusr.com/ugd/594ae5_3d1a5de1e60a4971baa50d47dc3a854e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c07ceb8f-a049-404e-957e-a5ae6af2fa70/firesawidakide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d32cb89a-3048-4980-af85-11aac06d1b1c/the_idea_factory.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3b30d12b-1f75-48f4-af8b-c4e55e5607c8/zarokanez.pdfIn PDF document text
    • https://b585a76b-fab5-4024-b0d2-f3ad95444197.filesusr.com/ugd/404203_5b576c558bd14d64854911f9ce8457fb.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xakajoziwibi/gineraritojid.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ede8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE8 5484 bytes
SHA-256: c99bc23cdcbc781e823947a343a587f78d2c62887b98be18615fc18df92eb832
font_01_sfnt_off00010041.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10041 12092 bytes
SHA-256: fa65bd1c72010aeac676fb1bb35e489585470d1d8b97c9e8302c1b67a1692c75